A number of processes for the production of synthetic polymers involve the preparation of particulate solids of the polymers as an end product initially suspended in gases such as steam, or vaporized liquids such as low molecular weight hydrocarbons. These mixtures are produced in many ways but those especially contemplated here involve the conversion of reaction mixtures comprising solutions of a polymer which are passed through contacting devices resulting in vaporization of solvents and formation of the particulate solids suspended in the vapor. In many cases, this vaporization is affected by contact with high-temperature vapors such as steam, or hot inert gases, such as nitrogen.
The use of ordinary cyclones for separating these solids from the gaseous suspensions has often been found to be unsatisfactory, particularly when the particles tend to adhere either to each other or to the interior surfaces of the separation apparatus while they are in a heated condition. Experience has shown that improvements in the apparatus are desired with respect to greater reduction in fouling, since downtime of the apparatus for the purpose of cleanout constitutes a substantial charge against the economics of the process.